Support systems for stator end windings of turbine generators must absorb vibration. The support system must control the forces which result from both steady-state and short-circuit conditions, and also allow controlled axial notion for thermal expansion. Atkinson et al., in U.S. Pat. No. 2,427,700, taught resin impregnated spacer blocks between adjacent end windings, to prevent end winding movement relative to one another during generator operation. The spacer blocks were made from a fibrous material, such as asbestos cloth, impregnated with a carbon filled phenolic resin.
Since the time of Atkinson et al., epoxy resins have come into popular use as insulation in electrical apparatus. However, no resin system has yet been found for bracing stator end windings which combines the features of low toxicity, low initial viscosity, and cure to give a heat distortion temperature of at least 100.degree. C. Other useful and advantages characteristics needed by this specialized system include: a room temperature gel time of between 40 to 90 minutes to allow adequate working time, low shrinkage, and good thin film drying characteristics at room temperature. It is essential that the resin film completely dry within at least 36 hours at up to 75% Relative Humidity, so that dust will not adhere to the end windings at the resin surface and cause an increase of surface conductivity.